Described herein are inserts for reducing sloshing in a bottle. The insert may be integrally formed in an outer shell of the bottle or removably insertable into the outer shell. The insert may include an elongate body extending between a first end opposite a second end; and an aperture defined by the elongate body and extending longitudinally through the elongate body between the first and second ends. The elongate body has an uncompressed state when removed from an outer shell and a compressed state when positioned in the outer shell. A diameter of the elongate body in the compressed state is less than or equal to a smallest diameter of the liquid retention compartment. The insert has a durometer between about 40 A and about 70 A. A volume of the insert is less than about 10% of a volume defined by the outer shell. The insert includes a compressible mesh material.